Risk of COVID‐19 infection among mobile extracorporeal membrane oxygenation team

Abstract Background and Aim The transport of coronavirus‐2019 (COVID‐19) patients on extracorporeal membrane oxygenation (ECMO) is a challenging situation, especially for healthcare workers (HCWs), due to the risk of cross‐infection. Hence, certain precautions are needed for their safety. The study aims to evaluate the risk of COVID‐19 transmission to HCWs who transport COVID‐19 patients on ECMO device. Methods A retrospective review of adult patients with COVID‐19 infection supported with ECMO and transported by ground route to the Medical Intensive Care Unit (MICU) at Hamad General Hospital (HGH) and a survey of HCWs involved in those cases. Results A total of 63 HCWs of the mobile ECMO team were exposed to COVID‐19‐positive patients on 199 occasions. HCWs exposure time was nearly 110 h, and the total transport distance was 1018 km. During the study period, only two of the mobile ECMO HCWs tested positive for COVID‐19. There was zero incidence of transfer‐associated injuries or accidents to HCWs. Conclusions The risk of COVID‐19 cross‐infection to the mobile ECMO team seems to be very low, provided that strict infection prevention and control measures are applied.

the chances of survival of critically ill COVID-19 patients. Extracorporeal membrane oxygenation (ECMO) has been suggested for severe acute respiratory distress syndrome (ARDS) secondary to SARS-CoV-2 infection. 12,13 Typically, ECMO is provided in tertiary or university-affiliated hospitals, and referrals are received within a geographical region or sometimes from abroad. Upon acceptance, the ECMO team will mobilize for bedside assessment and initiation of ECMO at the referring facility. Patients supported on ECMO will be transported to the ECMO center accompanied by the ECMO team. 13 Dissemination of infection to transport team members and staff from other facilities is a major concern. Direct and close patient contact, mechanical ventilation, airway suctioning, accidental disconnection of the breathing system, or extubation are all potential AGP and may be encountered during transport. 14,15 In addition, the confined transport environment may increase the risk of contamination.
Transport and retrieval of COVID-19 patients, particularly those critically ill who are put on ECMO, is challenging. The risk of HCWs cross-infection may be considerable; hence, specific guidance for HCWs' safety during transfer has been issued. [16][17][18] The mobile ECMO service at Hamad General Hospital (HGH) (a member of Hamad Medical Corporation (HMC); the premier healthcare provider in Qatar) was established in 2014 in preparation for the Middle East Respiratory Syndrome-Coronavirus (MERS-CoV) outbreak. 19 Before the COVID-19 pandemic, the ECMO transport team comprised two ECMO consultants, a perfusionist, two ECMO specialist nurses (a scrub plus circulating nurse), and a respiratory therapist. In addition, the emergency medical service (EMS) provided a critical care paramedic (CCP) and two ambulance paramedics. A rapid response vehicle and a designated ECMO ambulance were deployed for each ECMO activation to a referring facility, which was normally an isolation facility from the same governmental healthcare system. During the pandemic, the mobile ECMO team membership was reduced due to the feared high risk of HCWs cross-infection and overwhelming clinical demands. As a result, one ECMO consultant was deemed enough, and the respiratory therapist was less often included as they were in high demand in the COVID-19 units.
The mobile ECMO activation and mobilization is following the local and international guidance. 12,13,20 Our center encouraged early referral and transport of patients with ARDS. 21 Our protocol mandated full personal protective equipment (PPE) before entering the COVID-19 isolation facility ( Figure 1). PPE included waterresistant overhaul, shoe cover, gloves, N-95 respirator, goggles (or face shield), and headcover. Upon arrival, the team performed a full bedside assessment followed by a multidisciplinary discussion to support an informed decision of either rejection of ECMO, optimization, or cannulation and transfer to the ECMO center at HGH ( Figure 2

| Setting
Unidentifiable patient data were collected and analyzed, and the need for patient consent was waived.

| Participants
The subjects of the study were patients and HCWs. We conducted a retrospective review of all adult patients with confirmed COVID-19 supported with ECMO and transported by ground route to the MICU of HGH, Doha, Qatar, between March 1st 2020 and January 1st 2021. No sample size was calucated, we relied on the number of patients seed during the previously mentioned period.
We included all adult patients with confirmed COVID-19 infection who were cannulated and then transported by ambulance on ECMO to our tertiary center. We did not include patients with non-COVID pathology or following E-CPR. All members of the mobile ECMO team who went on any of the call-outs for assessment, cannulation, or transportation of those patients were invited to participate in the study. To investigate HCWs' infection with COVID-19, we distributed a consent form and study information sheet to all identified mobile ECMO team members. Upon consent, an electronic link to the survey was sent to all participants.
We report patients' demographics, the severity of their illness, and mobile ECMO team variables. The data extracted for each mission over the duration of the study included patient's demographics, relevant medical history, team composition, and location of referring facility, all of which were retrospectively extracted from the mission reports. The duration of mobile ECMO team members' exposure is defined as the time from entering the referring facility to the time of ECMO plug-in at the MICU at HGH. Outcome variables are confirmed mobile ECMO team member infection with COVID-19 during the study period and any untoward transport incidents.

| Variables
Continuous variables are expressed as mean/median and standard deviation (SD). Categorical variables are expressed as numbers and proportions.

| Statistical methods
Statistical analysis was conducted using Excel version 16.45 (Microsoft Corporation).

| RESULTS
During the study period, 34 mobile ECMO activations and cannulations were performed for patients with confirmed COVID-19 infection. Patients were predominantly males (30/34) and of relatively young age (mean 47.9, SD 9.25 years). Patients were critically ill with high acute physiology and chronic health evaluation-II (APACHE-II) score (mean 25.9, SD 4.95) and sequential organ failure assessment (SOFA) score (11.5 mean, SD 1.7). Thirty-three successful veno-venous and one veno-arterial ECMO cannulation were accomplished. Patients' demographics, the severity of illness, and clinical characteristics are presented in Table 1. A total of 63 different mobile ECMO team members were exposed to COVID-19 patients in a total of 199 episodes of Another study demonstrated a very low risk of COVID-19 contamination to EMS and reported an incidence of 0.57 infections/ 10,000 person-days over a similar study period. 31 Our study, however, is based on a higher number of COVID-19 ECMO patients transport missions and provides a more detailed description of the transport process, time of exposure, and examination of possible risk factors for HCWs cross-infection. We report over a period during which vaccines were not yet available in supervision; writingoriginal draft; writingreview and editing.

ACKNOWLEDGMENT
The publication of this article was funded by the Qatar National Library (QNL).

CONFLICTS OF INTEREST
Abdulqadir J. Nashwan is an Editorial Board member of Health Science Reports and coauthor of this article. He is excluded from TAWEL ET AL. | 5 of 7 editorial decision-making related to the acceptance of this article for publication in the journal. The authors declare no conflict of interest.

DATA AVAILABILITY STATEMENT
All data generated during this study are included in this published article.

ETHICS STATEMENT
The study was approved by the

TRANSPARENCY STATEMENT
The lead author Abdulqadir J. Nashwan affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.

SUPPORTING INFORMATION
Additional supporting information can be found online in the Supporting Information section at the end of this article.